Question: What is sea-spray?

Dave Sproson answered on 14 Jun 2011:

Hey Kiera,

Sea-spray is small droplets of sea water that are ejected from the surface of the ocean. This can happen either through the bursting of bubbles that come to the surface of the ocean after a wave breaks, or just by the wind ‘ripping’ droplets of water from the surface of the ocean — usually from the top (or ‘crest’) of a wave.

Sea-spray is important for many different reasons. The smallest droplets are so small that they can just float up into the air on the breeze. These can reflect sunlight back into space, helping to cool the planet, and they are also essential for forming clouds over the ocean. Clouds can’t really just form in perfectly clean air – they need something to be able to form on. Over land there are plenty of sources of small enough particles for clouds to form on, from pollutants from factories, from plants, or even bacteria which can be blown up into the air. Over the ocean, though, there aren’t nearly as many of these particles, so without sea-spray there would be many fewer clouds and so the planet would be warmer.

Larger sea-spray droplets (we think – this is what I’m trying to find out!) are important for controlling how much energy (or heat) is transferred from the ocean to the air. Some powerful weather systems, such as hurricanes and typhoons are powered by heat from the ocean, so it is really important for us to understand how this heat gets into the storms in order for us to be able to forecast them more accurately – any eventually be able to give people more warning that a hurricane is on the way.